1. Field of the Invention
The present invention relates to an information processing apparatus and method having an interface to which an external device is removably connected, and also relates to a computer program product.
2. Description of the Related Art
Universal serial bus (USB) connection for connecting a host machine and a plurality of peripherals (devices) through serial communication is widely prevalent as a method for connecting between electronic devices. The USB is an interface standard supporting hot swapping that makes it possible to connect or disconnect devices to or from a machine in operation.
Conventionally, when a USB device is connected to a USB interface of a computer, control information is transferred between the USB device and the computer. Through this information transfer process, an operating system (OS) acquires, from the USB device, and checks a descriptor that stores therein information unique to the USB device in question. The descriptor includes information called a “class” that represents an attribute of the USB device. From the class information, the OS determines a device driver appropriate for the USB device in question and automatically assigns the device driver to the USB device.
A special type of USB device is known in which a class different from that to which the USB device originally belongs is set. For example, recent years have witnessed applications of an integrated circuit (IC) card reader that is used through the USB connection. Meanwhile, many OSs are equipped as standard with class drivers that are compatible with a human interface device (HID) class. Setting a USB device that does not belong to the HID class as an HID-class USB device saves labor required for installing a device driver unique to the USB device in question, which enhances convenience.
For example, Japanese Patent Application Laid-open No. 2010-039616 discloses an IC card reader that is not originally categorized as an HID-class USB device, but is set to be categorized into the HID class to thereby use an HID-class device driver.
Japanese Patent Application Laid-open No. 2010-165128 discloses a technique that controls a USB device having a class different from its original one set therefor, through special control performed by an application via a generic USB device driver that does not represent a class driver of its original class. Japanese Patent Application Laid-open No. 2010-165128 describes an example, in which a magnetic card reader mounted as the HID class is used as a device for authentication. According to Japanese Patent Application Laid-open No. 2010-165128, a USB device in which a class different from its original one is set can be used.
To use a USB device for which a class different from that to which the USB device originally belongs is set, an application needs to be made available that can control such that the USB device to which a class driver of a different class is assigned operates properly. If some restrictions hamper use of this application, problems are that the USB device to which the class driver of a different class is assigned cannot be used and, moreover, unexpected operation may result.
The above-described technique disclosed in Japanese Patent Application Laid-open No. 2010-165128 assumes the use of an application for controlling the USB device. If the application cannot be used, therefore, the problem is not solved in that the USB device to which the class driver of a class different from that to which the USB device originally belongs is assigned may not be properly controlled.